How can we reconcile with human ideas of justice the destruction of the two captains and their fifties?

Were they not only doing their duty in carrying out the orders of their king? Why should they be destroyed with lightning for that? (see 2 Kings 1: ).

The key to this difficulty is found, I believe, in ver. 1, in reference to the third captain, who was spared. “Go down with him,” the angel said, “be not afraid of him.” It seems clear from this that Elijah did well to be afraid of the other two captains and their companies, who would have exceeded their mandate, which was simply to bring the prophet to the king, by killing him themselves :—lynching him in fact. Elijah thus acted in his own defence in the spirit of a prophet of judgment, enforcing the law and its penalties. What was fitting for him was not so for James and John, the servants of the Saviour of men, for they were “of His Spirit.”